Fog generator



FOG GENERATOR Filed April 29, 1965 2 Sheets-Sheet l INVENTORS KENNETHV.- ISKE WARD P. one m BY ED l2 Ar-rvs.

Dec. 22, 1964 K. v. FISKE ETAL FOG GENERATOR 2 Sheets-Sheet 2 FiledApril 29, 1963 United States Patent Ofiice 3,lfil,85 Patented Dec. 22,1964 3,l1,985 EGG GENERATGR Kenneth V. Fiske, Woodstock, and Edward P.Seder,

Antioch, llL, assignors of fifty percent to Velsicol ChemicalCorporation, tlhicago, iii, a corporation of lllinois and fifty percentto Burgess Vihro-crafters, lneorporated, Grayslake, lll., a corporationof Belaware Filed Apr. 29, E63, Ser. No. 276,469 Claims. (Cl. 43-123)This invention relates to fog penetration and more particularly to anapparatus for the generation of fogs of various materials, andparticularly fogs of solid and viscous liquid pesticides.

It has heretofore been known to apply certain materials, such asmedicants, pesticides, and the like, as a fog of a solution of thematerial to obtain wide and efficient distribution of the material intothe atmosphere or into confined spaces. For example DDT, a commoninsecticide, can be dissolved in a solvent, such as mineral oil and thenpumped through a spray nozzle or other device and then heated to createa fog. Although the common devices are useful for normally liquidmaterials which readily flow or dissolve in solvents, these devices areunsatisfactory when it was desired to create the fog of a solid or aviscous liquid or a material without solvent. Moreover, devices havingtubes of narrow diameter and/ or pump mechanisms quickly become pluggedif the material tends to form a sludge or precipitate from solution.

Therefore, one object of the present invention is to provide anapparatus for generating a fog of a solid, viscous liquid, ornon-readily dissolvable material.

Another object of the present invention is to provide an apparatus whicheliminates spray nozzles, pump mechanisms and coils of narrow internaldiameter.

Still another object of this invention is to provide a fog generationapparatus which is readily portable and contains a minimum of movingparts contacting the material which is to be generated into a fog.

These and other objects and advantages of the present invention will beapparent from the following specification and accompanying drawings, inwhich:

FIG. 1 is a longitudinal partial cross section of the apparatus of thepresent invention, and

FIG. 2 is a diagrammatic fragmentary side elevational view of seedplan-ting apparatus with the apparatus of FIG. 1 installed thereon andin operation therewith.

Referring to FIG. 1, this figure shows the apparatus of the presentinvention in detail. The apparatus comprises an electrically operatedair blower 5, which may be of the centrifugal force type as shown, aventuri tube 6 mounted in the discharge of blower 5, an elongated heateddischarge tube 7 extending from the discharge of venturi tube 6, a tank3%), preferably a cylindrical, annular tank, defined by the walls 8 and9, with wall 9 defining a cylindrical annular space and being in spacedrelationship with the external surface of discharge tube 7, an outletpipe 11 in the bottom of tank leading through Wall 8 to metering means,such as needle valve 12 as shown, and a branch tube 13 leading from themetering means, such as needle valve 12, to venturi tube 6 incommunication therewith at the throat 14 thereof.

More specifically, air blower 5 may comprise an electrically operatedblower motor (hidden from view by guard grill 15) in drivingrelationship with rotor 16 in housing 17. Venturi tube 6 may be acasting or a machined pipe or bar having an internal surface 18conforming to recognized venturi tube design and having a fian e 19 atits inlet end in connection with the housing 17 of blower 5 at itsdischarge, and a flange 20 at the discharge end of venturi tube 6 insupporting connection with gasket 21 and flange 22 on heated tube 7.

Tank lil may be conveniently constructed of Welded metal walls 8, 9, 23and 24, which are preferably of stainless steel when the material to begenerated into a fog has a corrosive effect, or may be of ordinary steelwhen said material is relatively non-corrosive. Access is provided totank It) by means of a fill pipe 25 at the top of tank 19 disposed inWall 8. Fill pipe 25 is normally covered by cover 26 which may be heldsecurely thereto by screw threads (not shown) or by set screw 27. Wall his in spaced relationship with the external surface of tube 7 and thisrelationship may be conveniently maintained by disposing a plurality ofspacers, such as hollow tube 28, and preferably at least three suchtubes equidistantly spaced from each other and longitudinally disposedwithin the annular space formed by, and in abutting communication with,the exterior surface of tube '7 and wall 9. Tank 10 is also held inposition by means of one or more supporting brackets 29 fastened toflange 22 and in supporting connection with wall 23, such as by beingheld in rigid connection therewith by bolt 30. Tank it) may also have adrain disposed therein, such as dnain 31 disposed in wall 3 normallyclosed by drain plug 32.

Metering means, such as needle valve 12, may be connected to pipes lland 13 by suitable connectors, such as tubing connectors 33. Pipe 13 mayalso be maintained in communication with venturi tube 6 at its throat 14by means of a threaded hollow plug 34 threaded into a perpendicular holebored in venturi tube 6 at its throat l4, and a third tubing connector35 fitted thereon and holding the end of pipe 13 which is opposite tovalve 12. The hollow plug or nozzle 34 also may serve as a control onthe amount of suction created in pipe 13 by adjusting the distance plug34 penetrates into venturi tube 6 at its throat 14. For example,satisfactory results are obtained when plug 34 penetrates to "a distanceof /2 of the diameter of throat 14.

The other remaining parts in PEG. 1 are primarily the burner units 36and 37 and their fuel supply apparatus. A plurality of vaporized fuelburners 36 and 37 are positioned facing the annular space between heatedtube 7 and wall 9 of tank ll), so that the flame therefrom is directedtoward the external surface of tube '7 and the heat passes through thesaid annular space. The fuel burners may be all the same size, such as0.014 inch pintle burner nozzles, shown as burner 36 or may be largerunits to supplying a larger quantity of heat, for example burner 37.Suitable fuel, such as liquefied gas fuel, for example compressedpropane, is supplied to burners 3e and 3'7 by lines 38 and 39 connectedto burners 3d and 37 by tubing connectors 4t) and 41 respectively. Lines33 and 39 are connected to a fuel distribution manifold 42 by tubingconnectors 4h. Manifold 42 is supplied with suitable fuel from a tank(not shown) through line 44 in which is disposed regulator valve 45 tocontrol the supply of fuel to the burners 36 and 37.

In one specific. embodiment of this invention the flow of material fromtank 1%) to venturi tube 6 is' facilitated by a vertical pipe 46'extending from the junction of pipe 11 and wall 8 into tank lit in whichare positioned a plurality of horizontal nipples 47 through whichtheliquid material from tank ill may readily flow. Use of this devicegreatly facilitates the flow of material from tank Ill and eliminatesplugging of the entrance to pipe ll, which J often occurs when theentrance to pipe 11 is merely an .2 rial in tank it? has at leastpartially melted if a solid, or is readily flowable if normally aliquid, air blower is started forcing a moving stream of air throughventuri tube 6 and heated tube '7 creating a vacuum in tube 1.3.Metering means, such as needle valve 12, is then adiusted to admit thedesired flow of material from tank It) to enter venturi tube 6, throughtube 23, where it is atomized by the stream of air and then vaporized inheated tube 7. A dense fog of the material in tank It) is thus obtainedat the discharge of tube 7. Once adjusted, the apparatus willautomatically and continuously generate the desired tog.

FIG. 2 illustrates the utilization of the apparatus of the presentinvention with conventional seed planting equipment to simultaneouslytreat seeds and soil with the fog of a pesticide. Referring to FIG. 2,the conventional seed planting equipment comprises a drawing bar 59which at one end is attached to pulling means, such as a farm tractor(not shown) and at the other end is in connection with the planting shoe:71, seed hopper 52, and body member 53. This connection may be obtainedthrough suitable linking members, such as member Body member 53 supportsthe fertilizer hopper 55, and itself. is supported by axle bearinghousing 56. In normal operation the seed planter is towed behind atractor or other vehicle, and the blade 57 of planting shoe 51 slicesopen the soil to a predetermined depth, usually from two to six inches.Simultaneously, seeds 58 from hopper 52 drop into the bottom of theopening in the soil, and fertilizer is spread upon the soil from hopper55 through flexible tubing 59. The Wheel 60, which also supports bodymember 53, compacts the soil 61 over seeds 58 to complete the planting.

In the improved planting operation performed with the apparatus of' hepresent invention, as illustrated in FIG. 2, the apparatus of FIG. 1 ismounted on body member 53 by means of suitable supporting brackets s2.Vaporized fuel, such as liquefied propane gas is supplied to the fuelsupply line 44, from a fuel tank (not shown), which may conveniently bemounted on body member 53. The discharge end of tube 7 of FIG. 1 isconnected to a flexible hose 645 which communicates with a rigid pipemounted in planting shoe 51. In operation, the fog generator isdischarged through flexible pipe 64 and pipe 65 into planting shoe 51,Where it settles onto the soil 6i and the seeds in the opening in thesoil. The seeds v53 also contact the fog as they pass through the shoe51 and drop to the soil. In this manner both seeds and soil are treatedwith pesticide by the apparatus of the present invention.

In a typical operation with the apparatus mounted as shown in FIG. 2,tank 1%) Was charged with solid technical heptachlor. Technicalheptachlor is a commercial product which usually contains about 72%, andmay contain from about 60% to about 95%, of heptachlor with theremainder being about 28%, but which may vary from about 5% to about40%, of related compounds occurring in the normal manufacturing process.The fuel burners which were supplied with liquefied propane gas aspreviously described, were ignited and subsequently melted the solidtechnical heptachlor in tank 1% by heating the solid at from about 140F. to about 250 F. The blower was started by connecting the motor to theelectrical sys tem of a tractor which was towing'the apparatus at a rateofyfour miles per hour. The needle valve 12 in FIG.

1 was then opened and the melted technical heptachlor was forced byvacuum into venturi tube 6 where it was atomized to a line liquid spray.The spray was vaporized w in tube .7 which was heated by the fuelburners at from about 600 to about 1000 F. to generate a dense fog ofthe technical heptachlor. The planting shoe 51 sliced open the soil toadep -1h of about three inches and inter-.

mittently corn seeds were dropped into the planting shoe 51 and henceinto the opening. Dense fog of technical heptachlor wasdischarged intothe shoe at a rate of about 1:5 45 grams per minute. In this manner,rows of corn seeds were planted in which both the seeds and the soilWere treated with technical heptachlor.

We claim:

1. A fog generator comprising an air blower, a venturi tube incommunication with and secured at its inlet end to the discharge end ofthe air blower, a discharge tube extending from and secured to thedischarge end of the venturi tube, an endwise closed tank mounted inannularly spaced relationship about said discharge tube, means forintroducing material to said tank to be heated therein, a liquid conduitin communication at one end with the interior of the tank, means in saidconduit for metering a heated liquid in its passage therethrough, theopposed end of said conduit being secured to and in communication withthe venturi tube at the throat thereof, fuel burner means leading to theannular space between the external surface of the discharge tube and thetank, and means for controlling a supply of fuel to the fuel burnermeans.

2. A fog generator comprising an air blower, a venturi tube incommunication with and secured at its inlet end to the discharge end ofthe air blower, a discharge tube extending from and secured to thedischarge end of the venturi tube, an endwise closed tank, spacer meansretaining said tank in annularly spaced relationship about saiddischarge tube, means for introducing material to said tank to be heatedtherein, a liquid conduit in communication at one end with the interiorof the tank, needle valve means in said conduit for metering a heatedliquid in its passage therethrough, the opposed end of said conduitbeing secured to and in communication with the venturi tube at thethroat thereof, fuel burner means leading to the annular space betweenthe external surface of the discharge tube and the tank, and means forcontrolling a supply of fuel to the fuel burner means.

3. A fog generator comprising an air blower, a venturi tube incommunication with and secured at its inlet end to the discharge end ofthe air blower, a discharge tube extending from and secured to thedischarge end of the venturi tube, an endwise closed tank mounted inannularly spaced relationship about said discharge tube, means forintroducing material to said tank to be heated therein, a liquid conduitin communication at one end with the interior of the tank, means in saidconduit for metering a heated liquid in its passage therethrough, theopposed end of said conduit being secured to and in communication withthe venturi tube at the throat thereof and terminating therein in atransversely adjustable aperturcd nozzle, fuel burner means leading tothe annular space between the external surface of the discharge tube andthe tank, and means for controlling a supply of fuel to the fuel burnermeans.

4. A fog generator comprising an air blower, a venturi tube incommunication with and secured at its inlet end to the discharge end ofthe air blower, a discharge tube extending from and secured to thedischarge end of the venturi tube, an endwise closed tank mounted inannularly spaced relationship about said discharge tube, means forintroducing material to said tank to be heated therein, a liquid conduitin communication at one end with the interior of the tank and anextension of said conduit projecting with the tank embodying a pluralityof spaced nipples, means in said conduit for metering a heated liquid inits passage therethrough, the opposed end of said conduit being securedto and in communication with the venturi tube at the throat thereof,fuel burner means including a plurality of angularly spaced nozzlesleading to the annular space between the external surface of thedischarge tube and the tank, and means for controlling a supply of fuelto the fuel burner means.

5. A generator for use in forming a fog from a ma terial, said generatorincluding: a tank having a top, a bottom, two ends, a passagewayextending approximately horizontally through the tank from end to end,and a fill opening in the top of the tank for introducing the materialinto the tank, said passageway being ofi-set in a downwardly directionfrom the center of said ends; a fogging tube extending through andsubstantially beyond the end of said passageway, said tube being smallerin cross section than the passageway to define a space between the tubeand the tank; a blower connected to one end of the tube to force airtherethrough; means to withdraw metered amounts of liquid from thetankand to introduce it into said end of the tube, said means includinga pipe communicating with the bottom of the tank and a connecting pipecommunicating with said end of the tube; and burner means about said endof the tube to heat said end of the tube with the combustion gasespassing through said space.

References Cited in the file of this patent UNITED STATES PATENTS1,587,736 Schenck June 8, 1926 2,012,973 Parker Sept. 3, 1935 2,422,024Levey et a1 June 10, 1947 2,662,332 McIntire Dec. 15, 1953 2,734,439Padrick Feb. 14, 1956 2,926,855 Dumet a1. Mar. 1, 1960 OTHER REFERENCESFrance, 61,798, Dec. 8, 1954, 1st. Addition of French Patent 1,051,128,Sept. 9, 1953.

1. A FOG GENERATOR COMPRISING AN AIR BLOWER, A VENTURITUBE INCOMMUNICATION WITH AND SECURED AT ITS INLET END TO THE DISCHARGE END OFTHE AIR BLOWER, A DISCHARGE TUBE EXTENDING FROM AND SECURED TO THEDISCHARGE END OF THE VENTURI TUBE, AN ENDWISE CLOSED TANK MOUNTED INANNULARLY SPACED RELATIONSHIP ABOUT SAID DISCHARGE TUBE, MEANS FORINTRODUCING MATERIAL TO SAID TANK TO BE HEATED THEREIN, A LIQUID CONDUITIN COMMUNICATION AT ONE END WITH THE INTERIOR OF THE TANK, MEANS IN SAIDCONDUIT FOR METERING A HEATED LIQUID IN ITS PASSAGE THERETHROUGH, THEOPPOSED END OF SAID CONDUIT BEING SECURED TO AND IN COMMUNICATION WITHTHE VENTURI TUBE AT THE THROAT THEREOF, FUEL BURNER MEANS LEADING TO THEANNULAR SPACE BETWEEN THE EXTERNAL SURFACE OF THE DISCHARGE TUBE AND THETANK, AND MEANS FOR CONTROLLING A SUPPLY OF FUEL TO THE FUEL BURNERMEANS.